Car parts priced at$500 in 2015→$494.62 in 2018

Historical Price Inflation for Car parts

Prices for Car Parts, 2015-2018 ($500)

According to the U.S. Bureau of Labor Statistics, prices for motor vehicle parts and equipment were
1.08% lower
in 2018 versus 2015.

Between 2015 and 2018:Car parts experienced an average inflation rate of -0.36% per year.
In other words, car parts costing $500 in the year 2015 would cost $494.62 in 2018 for an equivalent purchase.
Compared to the overall inflation rate of 1.58% during this same period, inflation for car parts was
lower.

In the year 2015: Pricing changed by -0.41%,
below the average yearly
change for car parts during the 2015-2018 time period.
Compared to inflation for all items in 2015 (0.12%), price inflation for car parts was
lower.

Price Inflation for Motor vehicle parts and equipment since 1977

Consumer Price Index, U.S. Bureau of Labor Statistics

Years with the largest changes in pricing:
1980 (12%),
1979 (9.64%),
and 1981 (6.08%).

How to calculate the inflation rate for car parts, 2015-2018

Then plug in historical CPI values from above. The CPI for Motor vehicle parts and equipment was 144.236 in the year 2015 and 142.685 in 2018:

142.685 / 144.236* $500 = $494.62

Therefore, according to U.S. Bureau of Labor Statistics, $500 in 2015 has the same "purchasing power" as $494.62 in 2018 (in the category of Motor vehicle parts and equipment).

Source: U.S. Bureau of Labor Statistics began tracking the Consumer Price Index for Motor vehicle parts and equipment in 1977. In addition to car parts, the index produces monthly data on changes in prices paid by urban consumers for a variety of other goods and services.